• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 554 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

MAX3232 charge pump caps?

Yoda
Prodigy 10 points
Other Parts Discussed in Thread: MAX3232

 

What is supposed to be the voltage/waveform seen at the charge caps on the MAX3232 ?

C1+ basically is at 3v and pulses up to 5.5v giving two 1uS pulses every 35uS

C1- basically is at zero and pulses up to 3v in the same way as above

C2+ is at zero and pulses up to 5.5v in the same pattern

C2- is at -5.5v (negative) and pulses "up" to -0.5v in the same pattern

 

 

  • 0
    TI__Guru**** 164796 points

    Hello Yoda,

    The signals you reported are normal.

    The charge pump repeats these two steps as needed to keep V+ and V- at a regulated voltage.

    1) Vcc charges C1 while C2 inverted charges V- capacitor
    2) Vcc + C1 charges C2 & V+ capacitor

    Basically, C1 helps 'double' VCC and C2 inverts that 'doubled' voltage.


    Regards,
    Ron Michallick